In contemporary oncology practices there is an increasing emphasis on concurrent evaluation of multiple genomic alterations within the biological pathways driving tumorigenesis. At the foundation of this paradigm shift are several commercially available tumor panels using next-generation sequencing to develop a more complete molecular blueprint of the tumor. Ideally, these would be used to identify clinically actionable variants that can be matched with available molecularly targeted therapy, regardless of the tumor site or histology. Currently, there is little information available on the post-analytic processes unique to next-generation sequencing platforms used by the companies offering these tests. Additionally, evidence of clinical validity showing an association between the genetic markers curated in these tests with treatment response to approved molecularly targeted therapies is lacking across all solid-tumor types. To date, there is no published data of improved outcomes when using the commercially available tests to guide treatment decisions. The uniqueness of these tests from other genomic applications used to guide clinical treatment decisions lie in the sequencing platforms used to generate large amounts of genomic data, which have their own related issues regarding analytic and clinical validity, necessary precursors to the evaluation of clinical utility. The generation and interpretation of these data will require new evidentiary standards for establishing not only clinical utility, but also analytical and clinical validity for this emerging paradigm in oncology practice.
Colorectal cancer is the third most common cancer and the second leading cause of cancer-related deaths in the United States. Screening has been shown to be effective in reducing colorectal cancer incidence and mortality. Colonoscopy, sigmoidoscopy, and fecal occult blood tests are all recommended screening tests that have widespread availability. Nevertheless, many people do not receive the evidence-based recommended screening for colorectal cancer. Additional stool-based methods have been developed that offer more options for colorectal cancer screening, including a variety of fecal DNA tests. The only fecal DNA test that is currently available commercially in the United States is ColoSure(TM), which is marketed as a non-invasive test that detects an epigenetic marker (methylated vimentin) associated with colorectal cancer and pre-cancerous adenomas. We examined the published literature on the analytic validity, clinical validity, and clinical utility of ColoSure and we briefly summarized the current colorectal cancer screening guidelines regarding fecal DNA testing. We also addressed the public health implications of the test and contextual issues surrounding the integration of fecal DNA testing into current colorectal cancer screening strategies. The primary goal was to provide a basic overview of ColoSure and identify gaps in knowledge and evidence that affect the recommendation and adoption of the test in colorectal cancer screening strategies.